The invention concerns a hearing aid of the kind which comprises a sound transducer, an analogue-digital converter, a digital processing and adjustment circuit for the processing of digital signals, corresponding to audio signals which are received by the transducer, memory units for the storage of data and programmes for the digital processing and adjustment circuit, a digital-analogue converter and a speaker.
A hearing aid of this known kind is described for example in the U.S. Pat. No. 4,972,487, which concerns a programmable hearing aid which also contains data logging means. With this data logger it can be registered how many times each programme is activated, and for how long each programme is used. By the reading out of the data registered, an audiologist or a fitter or the like can ascertain for how long and how many times the individual user of the hearing aid has used the individual programmes over an elapsed period of time.
Known hearing aids of this kind are normally sold to the user as a one-time service at a relatively high purchase price. In addition to the hearing aid itself, this purchase price also covers an obligation, which the hearing aid dealer undertakes, to provide the user with service with regard to subsequent adjustment, advice, maintenance etc. for a subsequent period. which is normally of 3-5 years. All repairs are covered by a guarantee of 1-2 years, which thereafter are paid for by the user, but these repairs can, however, be covered if extra insurance is taken out.
For several various reasons, it would be desirable if the hearing aids could be sold in connection with subscription arrangements in the same way as e.g. is known in connection with contact lenses, where a start fee is paid upon establishing a subscription agreement, after which regular subscription fees are paid which cover, e.g. an annual check-up of the eyesight and continuous deliveries of new lenses.
For the hearing aid dealer, such an arrangement would have the advantage that this would provide a continuous income. For the users of the hearing aids, the advantage would be that the relatively high one-time service price upon acquiring the hearing aid would be spread over a series of years, and the users will also have the advantage that providing the regular subscription fee is paid, they will be ensured that repairs, service etc. of the hearing aid will be carried out and moreover, that they will be able to have their hearing checked regularly in connection with the subscription.
However, such a subscription arrangement in connection with hearing aids requires that it is possible to stop the current services if the user does not pay the subscription fees, in the same way as the regular deliveries of new contact lenses can be stopped in connection with lens subscribers.
This is achieved in a hearing aid of the kind disclosed in the introduction which contains a counter element for the registration of the utilisation time and a storage unit for the storage of this data, and which is characteristic in that the counter element comprises a counter for the registration of the time the hearing aid has been used, that the storage unit for the storage of this data comprises a non-volatile memory in which the utilisation time is summed up, that the hearing aid is arranged in such a manner that a comparison is made between the contents of that part of the non-volatile memory in which the summed-up utilisation time is stored and one or more limit values, and that when one or more of the limit values is reached, a special function is initiated.
The total time for which the hearing aid is used will hereby be registered currently in the hearing aid, and when one or more limit values are exceeded, in that a limit value can be set e.g. for a subscription period, said limit values having been previously stored in the hearing aid, a special function will be initiated which indicates to the user that the subscription period has expired or is nearing expiry. The user can hereafter take the steps necessary for extending the subscription.
As disclosed in claim 2, it can be expedient for the special function which is initiated to consist of a deactivation of the hearing aid, in that e.g. when the limit value is exceeded, a disconnection of the hearing aid battery or other vital functions in the aid can be effected.
As characterized in claim 3, the special function can consist of an alarm arrangement, whereby in the event of a first limit value being exceeded, the user is made aware that the subscription period has expired or is nearing expiry, e.g. by the hearing aid emitting a short acoustic signal which is possibly repeated. If the subscription is not renewed, this can be combined with the deactivation of the hearing aid after a second limit value is exceeded.
Finally, as disclosed in claim 4, the exceeding of a limit value can initiate a changing of the parameters and/or programmes which have influence on the operation of the hearing aid, so that an updating of the function of the hearing aid can take place automatically after a certain period of time, either in connection with the expiration of a subscription period or at a random time determined by the dealer or the audiologist.
The renewal of the subscription can naturally take place by the user paying a visit to the dealer (audiologist), who will update the hearing aid by means of the PC equipment, which is normally used when the hearing aid is set for use. As disclosed in claim 5, it can be-expedient for this to be carried out when the hearing aid is arranged to detect special reactivation signals. The detection of such reactivation signals, which e.g. can be, coded signals, results in the updating of the hearing aid.
As disclosed in claim 6, this updating can, for example, consist of the counter for the summed-up utilisation time being set to zero, so that a new subscription period can be started, or as disclosed in claim 7, that the stored limit value or values are increased corresponding to a new subscription period. With the latter method, the further advantage is achieved that the time counter will thus always contain a measure of the total utilisation time.
Moreover, with the updating, it can be expedient for further changes to be made in the data and/or the programmes which are stored in the hearing aid, as disclosed in claim 8, whereby an automatic updating of the function of the hearing aid is effected. For example, this can be the case in connection with new users, where use is made of a habituation system. With such a habituation system, there will occur a gradual transition from no hearing aid to full compensation for the user""s loss of hearing.
For the user, however, it will be an inconvenience to have to visit the dealer/audiologist to have the hearing aid updated by means of the PC equipment, which the dealer uses for adjustment of the hearing aid.
As disclosed in claim 9, the hearing aid can therefore be supplied with reactivation signals by special audio signals being sent to the hearing aid""s microphone. For example, this can be effected by the user telephoning to the dealer/audiologist, or vice-versa, (for example when the subscription fee for the following period has been paid), and that the audiologist then transfers the code signals via the telephone connection white the user holds the hearing aid close to the telephone receiver. The updating can hereby be effected quickly without the user having to visit the dealer/audiologist.
Other methods by which audio signals can be transferred to the hearing aid can be envisaged. For example, the dealer/audiologist can send a postcard with an audio chip or a tape on which the coded audio signals have been recorded, or use can be made of the Internet to transfer audio signals to the user""s hearing aid. After a subscription fee has been paid, the user can thus get the coded signals transferred by calling an Internet address from a PC. The payment of the subscription fee can also possibly be made over the Internet, so that with a single call the user cannot only make the payment but also get the coded signals transferred to the hearing aid.
In connection with the use of coded audio signals as reactivation signals, use can be made, for example, of the DTMF signals (Dual Tone Multi-Frequency), for example well known from the telephone systems, where two simultaneous pure tones are used to signal a digit between 0 and 9. Such signals are relatively easy to detect in the hearing aid""s digital signal processing circuit, and at the same time an ordinary telephone keypad can be used as coding apparatus.
Finally, as disclosed in claim 10, the hearing aid can be arranged with a number of code keys, pushbuttons or the like, so that the reactivation signals can be entered by the user. This has the advantage that the code can be sent to the user in writing, expressed as the entries, which must be made, after which the user himself can key in the code at a convenient time.
In both cases it will be an advantage that the code is changed from time to time, so that the user cannot just copy a code from a previous subscription period, e.g. by recording the coded audio signals on tape, and use this for the subsequent subscription period(s).